1. Field of the Invention
The present invention relates to a heating apparatus for a chemical vapor deposition equipment.
2. Background of the Related Art
Known methods for heating chemical vapor deposition equipment include a lamp heating method, a method of using an integration type heater, and a method of using a susceptor that generates infrared or high frequency electromagnetic radiation.
The lamp heating methods may have heating regions divided into zones. A plurality of lamps (generally, 10-20 lamps), each of which corresponds to a zone, are spaced-apart at a regular interval, thus obtaining a desired temperature.
In direct resistance heating methods, the above-described integration type heater is used. In this method, electric power is supplied to terminals of a heater to obtain a desired heat.
In methods in which infrared or high frequency radiation is used, a particular gas is charged in a lamp, thus obtaining a desired heat using the light which is generated when the gas is charged in the lamp.
FIG. 1 shows a known heating device of a chemical vapor deposition apparatus. In FIG. 1, reference numeral 2 denotes a quartz plate, 3 denotes a wafer, and 4 denotes an Au-coating.
Some heating devices for chemical vapor deposition equipment require significant amounts of time to perform heating and cooling operations. For example, in the case of infrared or high frequency radiation heating, as shown in FIG. 2, the time required to increase the temperature of a wafer from room temperature to a predetermined high temperature is 10-15 minutes, and the time required to reduce the temperature is 60-120 minutes. Thus, much time is required, heat loss is increased, and the apparatus is inefficiently operated, and is non-economical.
In the case of a lamp heating method, which is an indirect heating method, as shown in FIG. 2, the time required to increase the temperature is 10-30 seconds, and the time required to reduce the temperature is 1-5 minutes. Although the lamp heating method provides quicker temperature increase and decrease times, the use of heating lamps also causes the temperature of a deposited metallic layer and the underlying silicon layer to be different. Therefore, when heating a large diameter wafer, it is impossible to obtain a uniform temperature distribution, and to properly control the temperature.